This invention relates to an apparatus for generating a fluid flow and, more particularly, to a linear fan assembly having commonly journalled airfoils whose circuitous motion imparts aerodynamic lift to an attached air frame.
Linear fan assemblies have been used to direct or respond to the flow of a fluid in applications such as a power plant for an aircraft, a blower for creating a forced fluid current, a wind mill or a water wheel for power generation. In each of these diverse applications, the linear fan assembly circulates a plurality of blades on a belt or chain in a closed path about two or more rotating members. In certain linear fan assemblies, the blades are pivotably adjustable for maintaining a fluid flow in a consistent direction relative to the path of the moving belt as the blades circulate.
If the linear fan assembly is deployed as a power plant for an aircraft, the blades of the linear fan are shaped as airfoils that, when moved through the air, provide lift to an attached air frame or fuselage. The lift output by the linear fan is modified by changing the inclination angle of the airfoils such as by means of an interconnection of each airfoil with a moveable control channel. Despite the known use of linear fans to power an aircraft, conventional linear fans have been heretofore incapable of providing a compact structure that optimizes the air flow through the configuration of the aircraft and its air frame.
The present invention solves these and other shortcomings in the prior art by providing an apparatus for generating a fluid flow which, in a presently preferred embodiment, includes two rotatable members carried in a spaced relationship by respective axes of rotation in a support frame and a motor operably coupled for powering at least one of the rotatable members. A drive belt connects the rotatable members and a plurality of blade pairs is coupled to the drive belt. Each of the blade pairs has first and second blades in which each blade has an inclination angle and is pivotably coupled to the drive belt along an axis generally parallel to the axes of rotation of the rotatable members. Each said first blade is commonly journalled with one of the second blades. A control mechanism is coupled to each of said blades for independently adjusting the inclination angle of each blade.
In certain embodiments, the control mechanism comprises a plurality of control channels attached to the support frame and each blade may be coupled with a control channel via a control link. When the control channel is moved relative to the drive belt, the inclination angle of each blade is adjusted independently of the inclination angle of the respective commonly journalled blade.
In other embodiments, an apparatus is provided for generating a fluid flow that comprises two rotatable members mounted to a support frame in a spaced relationship, wherein each said rotatable member is configured for rotation about respective, generally parallel axes. A motor is operably coupled for selectively rotating at least one of the rotatable members. Two drive belts connect the rotatable members and traverse respective paths each having an upper flight and a lower flight. Two control channels are attached to the support frame, wherein each control channel is associated with one of the drive belts. A plurality of spaced blades is coupled to at least one of the drive belts and a plurality of control links each couple one of the blades to one of the control channels. Each blade is commonly journalled with another blade along an axis generally parallel to the axes of rotation of the rotatable members. Each blade has an inclination angle that is independently adjustable relative to the inclination angle of its commonly journalled blade.
The present invention provides an aircraft, linear fan or similar device having a simplified fluid flow control system with an integrated lift, propulsion and steering system in the form of independent control channels controlling the inclination angles of independent sets of circulating airfoils. Fluid flow control is established by simply moving each control channel relative to the path of the circulating airfoils.
These and other objects and advantages of the present invention shall become more apparent from the accompanying drawings and description thereof.